The formula H2O is also the molecular formula of water. For non-molecular substances such as table salt, we represent the composition with an empirical formula. Sodium chloride is represented by NaCl, meaning that sodium and chlorine ratio in sodium chloride is 1 to 1. Again, the subscript 1 is omitted.
By Phil Myers. The annelids include earthworms, polychaete worms, and leeches. All members of the group are to some extent segmented, in other words, made up of segments that are formed by subdivisions that partially transect the body cavity.Segmentation is also called metamerism.y Phil Myers. The annelids include earthworms, polychaete worms, and leeches. All members of the group are to some extent segmented, in other words, made up of segments that are formed by subdivisions that partially transect the body cavity.
Annelida. The animals in the Annelida are segmented worms. They have no legs, and no hard skeleton. Unlike mollusks, annelid bodies are divided into many little segments, like rings joined together. There are many other kinds of worms, but only annelids are segmented this way.There are three main groups of annelids, the earthworms (and their relatives), the leeches, and a big group that lives in the ocean and are called polychaetes (pol-ee-keets).here are many other kinds of worms, but only annelids are segmented this way. There are three main groups of annelids, the earthworms (and their relatives), the leeches, and a big group that lives in the ocean and are called polychaetes (pol-ee-keets).